You can set the TTL (time to live) of a zone to whatever value you like including zero to force every lookup to go to the authoritative servers (do not do this,

You can set the TTL (time to live) of a zone to whatever value you like including zero to force every lookup to go to the authoritative servers (do not do this, it will make your site slow for users and your network administrators grouchy). Most dynamic dns providers have a default of 60 seconds. From the article it's hard to tell exactly what they are talking about, but it sounds like any of a number of schemes for abusing DNS as a federated database.